Annunciator system for internal combustion engines with provision for automatic shut down



Aug. 6,

1968 A. R. EMERSON 3,396,376

ANNUNCIATOR SYSTEM FOR INTERNAL COMBUSTION ENGINES WITH PROVISION FOR AUTOMATIC SHUT DOWN Filed Feb. 5, 1965 F "I W20 l H l 1 I R140 l4b ]/-l4c l i f let; 16c l 1 I: 7: 5 36 i 1 1 0 I w @SESJGO I I 38 1 l I 52 15 1 2 i I i 50 l I i l I 42 I I l I 'L CF40 L I VIZ "T Fig 1 TO CONTACT l6 +T0 LINE 20 Fig 2 INVENTOR Allen R. Emerson ATTORNEY United States Patent 3,396,376 ANNUNCIATOR SYSTEM FOR INTERNAL COMBUSTION ENGINES WITH PROVISION FOR AUTOMATIC SHUT DOWN Allan Rr Emerson, Dallas, Tex., assignor to Beta Corporation, a corporation of Texas Filed Feb. 5, 1965, Ser. No. 430,578 11 Claims. (Cl. 340-467) The present invention relates to annunciator systems and more particularly to an annunciator system especially adapted for indicating a malfunction in the operation of an internal combustion engine and automatically shutting down the engine upon the occurrence of a malfunction.

Internal combustion engines are utilized as a source of power in many different applications. In general, such engines are quite expensive and it is desirable that in the event of a malfunction, the engine be automatically shut down to prevent extensive damage or, in some instances, total destruction of the engine. Moreover, to facilitate repair and correction of the malfunction, it is desirable that an indication of the malfunction be provided subsequent to shut down of the engine.

The present invention provides an annunciator system especially adapted for use with internal combustion engines which fulfills these needs and which is characterized by a high degree of simplicity and reliability.

In accordance with the principles of the present invention, a group of signal responsive elements associated with a group of inter-related variables is provided for indicating the malfunction of an engine. For example, one of the variables may be responsive to excessive vibration, another of the variables may be responsive to water temperature and another variable may be responsive to the oil pressure. It will be appreciated that the number of variables will vary to a considerable extent dependent upon the size of the engine and the instrumentation available. There is also provided a capacitor which is charged when the equipment is operated and a switching device which is switched from a normally high impedance state to a low impedance state responsive to the capacitor being charged to a triggering voltage level. If one of the variables becomes abnormal when the capacitor is charged to the triggering voltage level, a signal is applied to operate the associated signal responsive element. When operated, the signal responsive element indicates the presence of the abnormal condition and shuts down the engine.

In accordance with a preferred embodiment of the invention, a plurality of parallel branch circuits are provided, each of the branch circuits comprising a normally open field contact element connected in series with the actuating terminals of a circuit breaker. The switching device is preferably a breakdown diode device, one terminal of the breakdown device being connected to each of the parallel branch circuits and the other terminal being connected to a capacitor. When the charge on the capacitor becomes equal to the breakover voltage of the device, the device will switch to the low impedance state if a conductive path is provided through the device. Thus, when one of the variables indicates a malfunction, it will provide a conductive path through the circuit breaker, permitting the capacitor to discharge and actuate the associated circuit breaker. Since the capacitor will be discharged in the course of actuating the circuit breaker associated with the first variable to become abnormal, the circuit breakers associated with variables which become abnormal subsequently will not be actuated and a desirable first out indication will be obtained, expediting the "ice correction of the malfunction. When the circuit breaker is actuated, a lever associated therewith will change positions, indicating the variable which first becomes abnormal. The circuit breaker will also be effective to ground or otherwise apply a signal of a character to shut down the engine. Although a mechanically latching type relay, such as a circuit breaker, is preferred practicing the invention, other types of indicating elements can be used as will become apparent from the description of the invention.

The features of the invention which are believed novel are set forth with particularity in the claims. Many objects and advantages of the invention will, however, become apparent to those skilled in the art as the following detailed description of a preferred embodiment of the invention unfolds when taken in conjunction with the appended drawings in which:

FIGURE 1 is a schematic diagram illustrating a pre ferred embodiment of the present invention; and

FIGURE 2 schematically illustrates an electrically latching relay suitable for use in practicing the present invention.

Turning now to FIGURE 1 of the drawings, there is schematically illustrated a preferred embodiment of the invention especially adapted for use with a spark ignition engine in which the energy for the spark is derived from a magneto. As shown in FIGURE 1, the magneto included within electrical system 10 has a primary winding 30. One side of the primary winding 30 is connected to ground and the other side of the primary winding is connected to ground through rotary contact 32. As is known in the art, a magneto is essentially an AC machine in which the field windings are rotated in a magnetic field. When the contact 32 is closed, a high voltage will be produced in the secondary winding (not shown), the high voltage produced in the secondary winding being utilized to fire a spark plug.

The primary winding 30 is connected through a variable resistor 34, a fixed resistor 36, a diode rectifier 38 and capacitor 40 to ground. As the primary winding is rotated in the magnetic field, an alternating current will be produced which is used to charge the capacitor 40 through the rectifier 38 and the resistors 34 and 36. The time required to charge the capacitor 40 to .a desired voltage level will, of course, be dependent upon the amplitude of the voltage induced in the winding 30 and the resistance of the resistors 34 and 36.

Thus, when starting of the engine is initiated, the magneto will be caused to turn, resulting in a voltage being induced in the winding 30. This voltage is used to charge the capacitor 40. The juncture between the diode rectifier 38 and the capacitor 40 is connected through diode breakover device 42 to line 13. The device 42 is suitably of the type known as the Shockley diode, which is disclosed in detail in United States Patent No. 2,855,524. As is known in the art, such devices normally exhibit a high impedance to the flow of current, but will switch to exhibit a low impedance to the flow of current in at least one direction when the voltage across the device exceeds the breakover voltage of the device.

Line 13 is commonly connected to a plurality of branch circuits 14a, 14b and 140. In this specific example, only three of the branch circuits are shown, although the number can vary dependent upon the complexity of the engine and the number of variables being monitored. Thus, each of the branch circuits includes a field contact 16 and a condition responsive element 18. Each of the condition responsive elements 18 is suitably connected by line 20 to the electrical system of the engine.

The condition responsive elements 18a-18c are each suitably a circuit breaker as shown with respect to 18a. Thus, each includes winding 50 coupled to moveable switch blade members 52 and 54. The circuit breaker is normally closed between the contacts 56 and 58 and normally open between the contacts 60 and 62. Terminal 56 is connected to one side of the coil 50, terminal 58 being connected to ground. Terminal 62 is also connected to ground, terminal 60 being connected to line 20. When the condition responsive element 18a is in a normal position, the switch lever 64 will be in the raised position as shown.

When the capacitor 40 is charged to a voltage equal to or in excess of the breakover voltage of the device 42, energy will be available at line 13 to energize the coil of the condition responsive element 18 associated with the first of field contacts 16 to close. It will be noted that the time required for the capacitor 40 to become charged can be varied by varying the resistance of resistor 34, if desired. Upon closure of one of the field contacts 16, current will fiow through the coil 50 of its associated condition responsive element 18, causing the element 18 to be open between contacts 52 and 56 and closed between contacts 60 and 62. Operation of the switch blades 52 and 54 will also be effective to move the switch handle 64 from the normally raised to a lower position, indicating that the device 18 has been operated. The switch handle 64 is mounted in such a manner that once it is placed in the lower position it will maintain the device open between contacts 56 and 58 and closed between contacts 60 and 62 even though current shall cease to fiow.

Thus, when one of the field contacts 16 indicates an abnormal condition subsequent to the capacitor 40 being charged to a voltage equal to or greater than the breakover voltage of the device 42, its associated condition responsive elements 18 is actuated, line 20 will be at ground tion responsive element 18 to indicate the presence of an abnormal condition. The condition responsive element will also apply a signal through line 20 to the electrical system of a character to cause the engine to become shut down.

It will be noted that so long as one of the condition responsive element 18 is actuated, line 20 will be at ground potential, preventing the capacitor 40 again becoming charged or a voltage being applied to the spark plugs of the associated engine. Also, the resistors 34 and 36 are of a high resistance such that the time required for the capacitor to be charged to the breakover voltage of device 42 is sufficiently long such that the variables which would normally indicate an abnormal condition when the motor is not operating, such as oil pressure, will have sufiicient time to attain a normal indication prior to the capacitor attaining such a charge level. Also, energy will be available at line 13 for operating one of the condition responsive elements 18 responsive to the associated variable indicating an abnormal condition only when the capacitor 40 is charged. Once the capacitor 40 is discharged responsive to \the presence of an abnormal condition, indicated by the closure of one of the field contacts 16, additional energy will not be available for actuating another one of the condition responsive devices 18. The system provided by the preferred embodiment of the present invention therefore functions as a first out annunciator system, expediting the discovery of the cause of shut down and simplifying repair procedures.

A mechanically latching circuit breaker is preferred for utilization as the condition responsive element 18 in view of its simplicity, ready availability, inherent reliability and low cost. However, other types of condition responsive elements, such as, for example, the electrically latching relay of FIGURE 2, can be utilized in practicing the invention.

Thus, a suitable configuration for an electrical latching condition responsive element 18 comprises a coil 70 connected at one side to ground. The element of FIGURE 2 includes normally closed contact member 71 and two normally open contact members 72. and 74. The other side of the 'coil 70 is connected through the normally closed contact member 71 to one of the fie-ld contacts 16. When the field contact 16 is closed subsequent to the end of the timing interval, current flows through the coil 70 energizing the relay and causing the contacts 72 and 74 to become closed and opening the contact 71. The contact 72 is suitably connected to line '20, as described previously with reference to FIGURE 2, for purposes of grounding the electrical system of the engine and shutting the same down. Contact 74 is suitably connected in series with a battery 76, normally provided in conjunction with an internal combustion engine and the coil 70. Thus, when relay contact 74 is closed, power will be applied from the battery through the coil 70, maintaining the relay coil energized. A lamp 98, suitably connected in shunt with coil 70, will be energized, indicating the presence of a malfunction. It will be noted that since the field contact 16 is connected to the relay coil through the normally closed contact member 71, the contact member 71 being open when the coil is energized, that the battery 76 will not provide power to other relay coils through the contacts of the first member to be energized. The desirable first out indication will therefore be obtained.

The foregoing description of a preferred embodiment of the invention is intended to be illustrative and not limiting of the invention defined in the appended claims, since many changes and modifications will become apparent to those skilled in the art.

What I claimed is:

1. An annunioator system for use with an internal combustion engine that comprises:

(a) a plurality of field contact members, each of said field contact members being open when an associated variable is normal and closed when the associated variable is abnormal;

(b) a plurality of parallel branch circuits each comprising one of said field contact members and an associated current sensitive device having a normal and an abnormal state;

(c) a capacitor;

(d) means including a resistor providing a charge path for said capacitor from a portion of an electrical system of an engine which is operated when starting of the engine is begun;

(e) a switching device having two terminals and connected by said two terminals between said capacitor and said parallel branch circuits, said switching device normally exhibiting a high impedance to the flow of current in the direction from said capacitor to said parallel branch circuits and capable of being switched to a low impedance state in said direction responsive to the charge on said capacitor being at least equal to the breakover voltage of said switching device;

(f) said capacitor being discharged through said switching device and one of said current sensitive devices responsive to the associated field contact member being closed when said capacitor is charged to a voltage at least equal to the breakover voltage of said switching device;

(g) means elfective responsive to the flow of current through said one current sensitive device for maintaining said one current sensitive device in the abnormal state; and

(h) means effective responsive to said one current sensitive device being in the abnormal state for indicating the presence of a malfunction and shutting down said engine.

2. An annunicator system for use with an internal cornbustion engine that comprises:

(a) a plurality of field contact members, each of said field contact members being open when an associated variable is normal and closedwhen the associated variable is abnormal;

(b) a plurality of parallel branch circuits each comprising one of said field contact members and an associated circuit breaker having a coil;

(c) a capacitor;

(d) means including a resistor providing a charge path for said capacitor from a portion of an electrical system of an engine which is operated when starting of the engine is begun;

(e) a switching device having two terminals and connected by said two terminals between said capacitor .and said parallel branch circuits, said switching device normally exhibiting a high impedance to the flow of current in the direction from said capacitor to said parallel branch circuits and capable of being switched to a low impedance state in said direction sponsive to the charge on said capacitor being at least equal to the break-over voltage of said switching device;

(f) said capacitor being discharged through said switching device and the coil of one of said circuit breakers responsive to the associated field contact member being closed when said capacitor is charged to a voltage at least equal to the breakover voltage of said switching device;

(g) means effective responsive to the flow of current through the coil of said circuit breaker for maintaining said circuit breaker in an operated condition; and

(b) means effective responsive to said circuit breaker being operated for indicating the presence of a malfunction and shutting down said engine.

3. In combination:

(a) an internal combustion engine having an electrical system including a component which is operated when starting of the engine is begun;

(b) a capacitor;

(c) means including a resistor and a diode rectifier connected between said component and said capacitor for charging said capacitor when said component is operated;

(d) a diode switching device connected at one terminal to one side of said capacitor, said diode switching device normally exhibiting a high impedance to the flow of current in a direction to discharge said capacitor but capable of being switched to a low impedance state in said direction responsive to the charge on said capacitor being equal to the breakover voltage of said diode switching device;

(e) a plurality of parallel branch circuits connected at one side to the other terminal of said diode switching device and at the other side to the other side of said capacitor;

(f) each of said branch circuits including a normally open field contact member and a current sensitive device having a normal and an abnormal state;

(g) one of said current sensitive means being placed in the abnormal state by the discharge of said capacitor responsive to the associated field contact being closed when said capacitor is charged to a voltage at least equal to the breakover voltage of said diode switching device;

(h) said current sensitive device when placed in the abnormal state remaining in said abnormal state subsequent to the discharge of said capacitor and indicating the presence of the abnormal state; and

(i) means effective responsive to one of said current sensitive elements being in the abnormal state for shutting down said engine.

4. A combination as defined in claim 3 wherein said component of the electrical system is a magneto, said capacitor being connected to a winding of said magneto through said resistor and said diode rectifier.

5. A combination as defined in claim 3 wherein each said current sensitive means is a circuit breaker having a coil connected in series with the associated field contact member, a normally open contact member, a manually operable switch handle and means etfective responsive to the fiow of current through said coil for closing said normally open contact member and placing said switch handle in an operated position, said switch handle being effective when in the operated position to hold said contact member in a closed position, said means effective for shutting down said engine being connected through said normally open contact member.

6. A combination as defined in claim 4 wherein said means effective responsive to one of said current sensitive means being in the abnormal state for shutting down said engine comprises means connecting a winding of said magneto to ground.

7. A combination as defined in claim 3 wherein each said current sensitive means comprises first and second normally open contact members, a normally closed contact member, a coil connected in series with the associated field contact member and the normally closed contact member, means for closing said first and second normally open contact members and opening said normally closed contact member upon the discharge of the capacitor through said coil, and further including means connected to said first normally open contact member for maintaining said coil energized after said capacitor is discharged, said means etfective for shutting down said engine being connected through said second normally open contact member.

8. An annunciator system for indicating the presence of a malfunction and shutting down associated equipment that comprises:

(a) a group of signal responsive means associated with an interrelated group of variables;

(b) a capacitor;

(0) switching means having first and second electrodes,

said switching means normally exhibiting a high impedance between said two electrodes but being switched to exhibit a low impedance between said two electrodes responsive to said capacitor being charged to a triggering voltage level;

(d) means for charging said capacitor when said equipment is operated; and

(e) means connecting said switching means by said first and second electrodes to apply to one of said signal responsive means a signal to operate said one signal responsive means responsive to the associated variable being abnormal when said capacitor is charged to said triggering voltage level, said signal responsive means being elfective when operated to indicate a malfunction by said associated variable and shut down said equipment.

9. An annunciator system that comprises:

(a) a group of current sensitive elements associated with an interrelated group of variables;

(b) each said variables when abnormal indicating a malfunction of an engine having an electrical system;

(c) a capacitor;

(d) means including a resistor providing a charge path for said capacitor from a portion of said electrical system which is energized only when said engine is operated;

(e) semiconductor diode switching means which normally exhibits a high impedance between two terminals and which is switched to exhibit a low impedance between said two terminals when the voltage across said device exceeds the breakover voltage of the device and remains in said low impedance state so long as holding current flows through said two terminals;

(f) means connecting said diode semiconductor switching device by said two terminals between said capacitor and said group of current sensitive elements for operating one of said current sensitive elements responsive to its associated variable being abnormal when said capacitor is charged to a voltage at least equal to the breakover voltage of said diode semiconductor switching device; and g) means efifective when said one current sensitive element is operated for indicating a malfunction of the associated variable and shutting down said engine. 10. An annunciator system as defined in claim 9 including means for maintaining said element in the operated condition after said capacitor is discharged.

11. An annunciator system as defined in claim 9 wherein the time constant of the charge path is sufiiciently long that said capacitor is only charged to said breakover voltage after a time interval greater than is required to shut down said engine when stopping and reach normal operation when starting.

No references cited.

THOMAS B. HABECKER, Primary Examiner. 

1. AN ANNUNICATOR SYSTEM FOR USE WITH AN INTERNAL COMBUSTION ENGINE THAT COMPRISES: (A) A PLURALITY OF FIELD CONTACT MEMBERS, EACH OF SAID FIELD CONTACT MEMBERS BEING OPEN WHEN AN ASSOCIATED VARIABLE IS NORMAL AND CLOSED WHEN THE ASSOCIATED VARIABLE IS ABNORMAL; (B) A PLURALITY OF PARALLEL BRANCH CIRCUITS EACH COMPRISING ONE OF SAID FIELD CONTACT MEMBERS AND AN ASSOCIATED CURRENT SENSITIVE DEVICE HAVING A NORMAL AND AN ABNORMAK STATE; (C) A CAPACITOR; (D) MEANS INCLUDING A RESISTOR PROVIDING A CHARGE PATH FOR SAID CAPACITOR FROM A PORTION OF AN ELECTRICAL SYSTEM OF AN ENGINE WHICH IS OPERATED WHEN STARTING OF THE ENGINE IS BEGUN; (E) A SWITCHING DEVICE HAVING TWO TERMINALS AND CONNECTED BY SAID TWO TERMINAL BETWEEN SAID CAPACITOR AND SAID PARALLEL BRANCH CIRCUITS, SAID SWITCHING DEVICE NORMALLY EXHIBITING A HIGH IMPEDANCE TO THE FLOW OF CURRENT IN THE DIRECTION FROM SAID CAPACITOR TO SAID PARALLEL BRANCH CIRCUITS AND CAPABLE OF BEING SWITCHED TO A LOW IMPEDANCE STATE IN SAID DIRECTION RESPONSIVE TO THE CHARGE ON SAID CAPACITOR BEING AT LEAST EQUAL TO THE BREAKOVER VOLTAGE OF SAID SWITCHING DEVICE; (F) SAID CAPACITOR BEING DISCHARGED THROUGH SAID SWITCHING DEVICE AND ONE OF SAID CURRENT SENSITIVE DEVICES RESPONSIVE TO THE ASSOCIATED FIELD CONTACT MEMBER BEING CLOSED WHEN SAID CAPACITOR IS CHARGED TO A VOLTAGE AT LEAST EQUAL TO THE BREAKOVER VOLTAGE OF SAID SWITCHING DEVICE; (G) MEANS EFFECTIVE RESPONSIVE TO THE FLOW OF CURRENT THROUGH SAID ONE CURRENT SENSITIVE DEVICE FOR MAINTAINING SAID ONE CURRENT SENSITIVE DEVICE IN THE ABNORMAL STATE; AND (H) MEANS EFFECTIVE RESPONSIVE TO SAID ONE CURRENT SENSITIVE DEVICE BEING IN THE ABNORMAL STATE FOR INDICATING THE PRESENCE OF A MALFUNCTION AND SHUTTING DOWN SAID ENGINE. 